Tag Archives: Bishan Park

The Grey-rumped Treeswifts of Bishan Park (Part 2)

Contributed by Jensen Seah.

After reading the Burung Singapura’s post on the Grey-rumped Treeswifts at Bishan Park, I went to look for my images of these treeswifts taken there early this year. I think they will add to the nesting behavior of these treeswifts here.

Grey Rumped Treeswift male 21 Mar 15 - Bishan Park nesting 3

I stumbled on this male guarding the newly laid egg on the 20th March 2015. This photo was taken the next day and you can see the egg was almost hanging out the tiny nest. In fact you can hardly see the nest if not for the egg. I really wonder how the parents were able to keep it in the nest when the the branch start swaying on a windy day. Incubating the egg must be a very delicate juggling act. I went back 2 weeks later and the parents were still incubating the egg. At least we know that incubation takes more than 2 weeks. Unfortunately I was not able to check the hatching later on.

Grey-rumped Treeswift 13 June 15 - Bishan Park 3

This was another nesting at another part of the park. Taken on 13th June, the chick looked like close to fledging but I was not able to tell how old this chick was. A week later it had moved out of the nest. I like to think it may had just fledged the day or two before and not predated. I could not find it around the following week.

Grey-rumped Treeswift 13 June 15 - Bishan Park 4

The same chick taken on the same day. The wings were still not fully formed. It must have moved along the branch to get a feel of the surrounding. Based on the dates, this may be the sub-adult that Seng Alvin photographed recently at the park. I hope my ad-hoc records will in some ways help to add to its breeding behavior. If you have any other records of these treeswifts to share, you can post it on the Singapore Bird Group’s Facebook page.

Crested Goshawks preying on Palm Roosting Bats.

The Crested Goshawk, Accipiter Trivirgatus, is a rare and only resident accipiter in Singapore. The first breeding attempt was recorded from the Singapore Botanic Gardens in 1987 (SINAV 2-1). Sporadic sightings at Kent Ridge Park in 1993/94 and P.Ubin in 2004/5 followed. The first successful breeding was most probably the one at the Japanese Gardens in 2011. Before that in 2010, we had several records of juveniles at the Singapore Zoo (Feb), Ang Mo Kio and Chinese Gardens (December). These were the first signs of this resident spreading across the island. Since then we have received more breeding records from Sentosa, Singapore Botanic Gardens, Singapore Zoo,  Venus Drive, and Ang Mo Kio. The latest was a pair nesting in a Khaya senegalensis at Bishan Park, the subject of this article.

Adult Goshawk looking for bats in the palm fonds

Adult Goshawk looking for bats among the fonds of the Chinese Fan Palm.

Recently See Toh Yew Wai took Con Foley and I to document the feeding of the juvenile by its parents. What we saw was something most extraordinary. We are not sure if this has been documented before. The parent was seen moving in between the fonds of the Chinese Fan Palm Livistona Chinensis. We thought it was trying to hide from us, but it then flew out with a bat in its talons at around 9.30 am. It was actually looking for the bats roosting under the fonds instead of hunting for the usual prey like Rock Pigeons and Javan Mynas on the fly.

A common Frut Bat is still alive.

The bat looks like the Common Fruit Bat. It was still alive when caught. The Goshawk started pulling out the furs from its neck before tearing out the flesh.

We are not sure how the Goshawk know where to look for the bats. Is it something it learnt from its parent? Or did it noticed the roosting habits of the bats by chance or heard their calls? Whatever the case, this is definitely a more efficient way of hunting. The next day, Con Foley went back and saw the parent again looking for bats among the palms there. But this time round it was not able to find any. Could the bats moved out after being raided yesterday? Thankfully Con persisted with a third visit and saw the juvenile this time catching a bat on his own without the parent around. So the parent must have taught this to its young.

Adult Crested Goshawk tearing away the flesh of the Common Fruit Bat

Adult Crested Goshawk tearing away the flesh of the Common Fruit Bat.

The parent flew to the open branch of the Tembusu tree and began tearing open the bat with its hooked beak. It started feeding oblivious to our presence. The bat was still alive but surprisingly did not struggle or squeal. Nature can be really cruel. .

Start to call to its young to come to feed.

After finishing about half the bat, it started calling for its young to come to feed instead of bringing the bat to the young. This is one way to get the juvenile to do more flying.

The Juvenile flew in and start asking for the food

The Juvenile was hiding at a nearby tree and answered the parent’s call. It then flew to the Tembusu where the parent was waiting. It started flapping its wings and called for the parent to bring over the food.


The parent at one stage came down to the ground. The juvenile followed but later decided to fly back to the branch. From this shot you can see that the eyes of the juvenile is light grey unlike the adult which is yelllow.

The moment when the parent pass over the Fruit Bat to its young

But in the end it had to fly back up to the same branch as the parent where the bat was passed over to it. The juvenile is below.

Claining its prizeThe juvenile white underside is speckled with brown spots. We estimate that this juvenile to be about two months old.

It did not eat the bat straight away but held on to it. It could be checking if there are any other predators around to steal its meal. After a good five minutes, it decided to fly to a higher perch at a Khaya Tree that has a thicker foliage. We did not follow it so as not to disturb it’s feeding. But later on it was seen perched high up calling again without the bat.

A video of the feeding at https://youtu.be/foX7NWzAJ7Y.

Reference: The Avifauna of Singapore. 2009. Lim Kim Seng. Thanks to See Toh Yew Wai for bringing us there and Con Foley for sharing his observations with me. Many thanks to Ender Tey for sharing this nesting record with us.